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> Unreal Engine API Reference > Plugins > DynamicMesh > FRemesher

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FRemesher

[FRemesher](API\Plugins\DynamicMesh\FRemesher) implements edge flip/split/collapse/smooth Remeshing.

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Inheritance Hierarchy

FMeshRefinerBase

FRemesher

FSubRegionRemesher

References

Module	DynamicMesh
Header	/Engine/Plugins/Experimental/GeometryProcessing/Source/DynamicMesh/Public/Remesher.h
Include	#include "Remesher.h"

Syntax

class FRemesher : public FMeshRefinerBase

Remarks

FRemesher implements edge flip/split/collapse/smooth Remeshing. The basic process is very similar to the one described in: A Remeshing Approach to Multiresolution Modeling. Botsch & Kobbelt, SGP 2004. https://graphics.uni-bielefeld.de/publications/sgp04.pdf

In the iterative usage, each call to BasicRemeshPass() makes a pass over the mesh and attempts to update the topology and shape to satisfy the target criteria. This function iterates over the mesh edges and calls ProcessEdge(), which tries to Collapse, then Split, then Flip the edge. After the topology pass, we optionally do a full-mesh Smoothing pass, and a full-mesh Reprojection pass, to project onto a target surface.

A highly flexible constraint system can be used to control what is allowed to happen to individual edges and vertices, as well as Project vertices onto arbitrary proejction targets. This is done via FMeshConstraints which is set in the MeshRefinerBase base class.

Many aspects of the algorithm can be controlled by the public variables in the block below. In addition many of the core internal functions can be overriden to customize behavior. Various callbacks functions are called when topology changes occur which allows you to for instance track changed regions of the mesh.

Variables

	Name	Description
bool	bEnableCollapses	Controls whether edge collapses are allowed during remeshing pass
bool	bEnableFlips	Configuration variables and flagsControls whether edge-flips are allowed during remeshing pass
bool	bEnableParallelProjection	Enable parallel projection. Only applied in AfterRefinement mode
bool	bEnableParallelSmooth	Enable parallel smoothing.
bool	bEnableSmoothing	Controls whether vertex smoothing is applied during remeshing pass
bool	bEnableSmoothInPlace	If smoothing is done in-place, we don't need an extra buffer, but also there will some randomness introduced in results.
bool	bEnableSplits	Controls whether edge splits are allowed during remeshing pass
bool	bMeshIsClosed	We can avoid some checks/etc if we know that the mesh has no boundary edges.
bool	bPreventNormalFlips	Controls whether we try to prevent normal flips inside operations and smoothing.
int	COUNT_COLLAPSES
int	COUNT_FLIPS
int	COUNT_SPLITS	Testing/debug/profiling stuff profiling functions, turn on ENABLE_PROFILING to see output in console
TFunction< FVec...	CustomSmoothF	Override default smoothing function
TFunction< doub...	CustomSmoothSpeedF	Override constant SmoothSpeedT with function
int	MaxEdgeID
double	MaxEdgeLength	Maximum target edge length. Edges longer than this will be split if possible.
double	MinEdgeLength	Minimum target edge length. Edges shorter than this will be collapsed if possible.
int	ModifiedEdgesLastPass	Number of edges that were modified in previous Remesh pass.
const int	ModuloPrime	StartEdges() and GetNextEdge() control the iteration over edges that will be refined.
double	SmoothSpeedT	Smoothing speed, in range [0,1]
ESmoothTypes	SmoothType	Type of smoothing that will be applied unless overridden by CustomSmoothF
TArray< bool >	TempFlagBuffer
TDynamicVector<...	TempPosBuffer

Constructors

	Name	Description
	FRemesher()
	FRemesher ( FDynamicMesh3* MeshIn )	Public API

Functions

	Name	Description
void	ApplyToProjectVertices ( const TFunction< void>& Verte... )
void	ApplyToSmoothVertices ( const TFunction< void>& Verte... )	FullSmoothPass_Buffer this to calls VertexSmoothFunc for each vertex of the mesh.
void	ApplyVertexBuffer ( bool bParallel )
void	BasicRemeshPass()	Linear edge-refinement pass, followed by smoothing and projection
FVector3d	ComputeSmoothedVertexPos ( int VertexID, TFunction< FVector3d..., bool& bModified )	Computes smoothed vertex position w/ proper constraints/etc. Does not modify mesh.
bool	EnableInlineProjection()	This just lets us write more concise code
void	FullProjectionPass()	Project vertices onto projection target.
void	FullSmoothPass_Buffer ( bool bParallel )	Applies a smoothing pass to the mesh, storing intermediate positions in a buffer and then writing them at the end (so, no order effect)
int	GetNextEdge ( int CurEdgeID, bool& bDone )
FVector3d	GetProjectedCollapsePosition ( int VertexID, const FVector3d& vNewPos )	Used by collapse-edge to get projected position for new vertex
TFunction< F...	GetSmoothFunction()	Returns the function we want to use to compute a smoothed vertex position - will be CustomSmoothF if set, otherwise one of cotan/meanvalue/uniform
void	InitializeVertexBufferForPass()
void	OnEdgeCollapse ( int EdgeID, int VertexA, int VertexB, const FDynamicMesh3::FEdgeCollapseI... )	Callback for subclasses to override to implement custom behavior
void	OnEdgeFlip ( int EdgeID, const FDynamicMesh3::FEdgeFlipInfo ... )	Callback for subclasses to override to implement custom behavior
void	OnEdgeSplit ( int EdgeID, int VertexA, int VertexB, const FDynamicMesh3::FEdgeSplitInfo... )	Callbacks and in-progress informationCallback for subclasses to override to implement custom behavior
void	Precompute()	We can speed things up if we precompute some invariants.
EProcessResu...	ProcessEdge ( int edgeID )
void	ProfileBeginCollapse()
void	ProfileBeginFlip()
void	ProfileBeginOps()
void	ProfileBeginPass()
void	ProfileBeginProject()
void	ProfileBeginSmooth()
void	ProfileBeginSplit()
void	ProfileEndCollapse()
void	ProfileEndFlip()
void	ProfileEndOps()
void	ProfileEndPass()
void	ProfileEndProject()
void	ProfileEndSmooth()
void	ProfileEndSplit()
void	ProjectVertex ( int VertexID, IProjectionTarget* UseTarget )
void	SetTargetEdgeLength ( double fLength )	Set min/max edge-lengths to sane values for given target edge length
int	StartEdges()
void	UpdateAfterSplit ( int edgeID, int va, int vb, const FDynamicMesh3::FEdgeSplitInfo... )	After we split an edge, we have created a new edge and a new vertex.

Enums

	Name	Description
	EProcessResult
	ESmoothTypes	Built-in Smoothing types

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